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Twenty-eight HLA alleles of the A and B loci were determined in 23 American Blacks and 50 Caucasians with primary ankylosing spondylitis (AS). The prevalence of HLA B27 was significantly increased in American Black patients (48 per cent) vs Black controls (two per cent), but was much less than the 94 per cent found in Caucasian patients (controls eight per cent). The lower prevalence of B27 in American Black patients vs Caucasian patients was significant (p < 0.001), and indicated that susceptibility to AS is not as closely associated with B27 in Blacks as in Caucasians. No other HLA antigen was significantly associated with AS in either racial group. Among B27 positive individuals, the relative risk of developing AS was significantly lower in American Blacks than in Caucasians. These data indicate that for diagnostic purposes, the absence of B27 is less important in ruling out AS in Blacks than in Caucasians.
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Antígeno HLA-B27 , Espondilitis Anquilosante , Humanos , Estados Unidos/epidemiología , Antígeno HLA-B27/genética , Espondilitis Anquilosante/epidemiología , Riesgo , Antígenos HLA , Población Blanca/genéticaRESUMEN
Many studies examine how the landscape affects memory-informed movement patterns, but very few examine how memory-informed foragers influence the landscape. This reverse relationship is an important factor in preventing the continued decline of many ecosystem services. We investigate this question in the context of crop pollination services by wild bees, a critical ecosystem service that is in steep decline. Many studies suggest that adding wild flower patches near crops can result in higher crop pollination services, but specific advice pertaining to the optimal location and density of these wild flower patches is lacking, as well as any estimate of the expected change in crop pollination services. In this work, we seek to understand what is the optimal placement of a flower patch relative to a single crop field, during crop bloom and considering spatial factors alone. We develop an individual based model of memory-based foraging by bumble bees to simulate bee movement from a single nest while the crop is in bloom, and measure the resulting crop pollination services. We consider a single crop field enhanced with a wild flower patch in a variable location, and measure crop flower visitation over the course of a single day. We analyze the pollination intensity and spatial distribution of flower visits to determine optimal wild flower patch placement for an isolated crop field. We find that the spatial arrangement of crop and wild flower patch have a significant effect on the number of crop flower visits, and that these effects arise from the memory-informed foraging pattern. The most effective planting locations are either in the centre of the crop field or on the far side of the crop field, away from the single bumble bee nest.
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Ecosistema , Polinización , Animales , Abejas , Productos Agrícolas , FloresRESUMEN
The rationale of this study was to examine the effectiveness of 6-month high-impact step aerobics (SA) or moderate-intensity resistance training exercise (RT) on bone mineral density (BMD) and bone bending strength in sedentary women. Results show that SA enhanced BMD in the heel, lower leg, and lumbar spine 2. INTRODUCTION: To determine the effectiveness of 6 months of high-impact step aerobics (SA) or moderate-intensity resistance training (RT) on areal bone mineral density (aBMD) and tibial bending strength in sedentary premenopausal women. METHODS: Sixty-nine women (20-35 years old) who were randomly assigned to RT (n = 22), SA (n = 26), or non-treatment control (CON, n = 21) groups completed the study. SA had a minimum of 50 high-impact landings each training session. RT had a periodized lower body resistance training program incorporating eight exercises (65-85% of 1 repetition maximum: 1-RM). Both RT and SA met 3 times weekly. aBMD was assessed using dual X-ray absorptiometry (DXA). Tibial bending strength was assessed using mechanical response tissue analysis (MRTA). Measurements at 6 months were compared to baseline using ANCOVA, adjusted for baseline measures and covariates with α = 0.05. RESULTS: Calcaneus aBMD (0.0176 vs -0.0019 or -0.0009 g/cm2 relative to RT, p < 0.004, and CON, p < 0.006, respectively), lower leg aBMD (0.0105 vs -0.0036 g/cm2, relative to RT, p = 0.02), and lumbar spine 2 (L2) aBMD (0.0082 vs -0.0157 g/cm2 relative to CON, p < 0.02) were significantly greater in the SA group after 6 months. Tibial bending strength and bone resorption biomarkers were unchanged in all three groups after 6 months. CONCLUSION: Sedentary premenopausal women engaging in 6 months of high-impact aerobic exercise improved aBMD in the calcaneus, lower leg, and L2.
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Densidad Ósea , Entrenamiento de Fuerza , Absorciometría de Fotón , Adulto , Ejercicio Físico , Femenino , Humanos , Premenopausia , Adulto JovenRESUMEN
Understanding the distribution of an event duration time is essential in many studies. The exact time to the event is often unavailable, and thus so is the full event duration. By linking relevant longitudinal measures to the event duration, we propose to estimate the duration distribution via the first-hitting-time model (e.g. Lee and Whitmore in Stat Sci 21(4):501-513, 2006). The longitudinal measures are assumed to follow a Wiener process with random drift. We apply a variant of the MCEM algorithm to compute likelihood-based estimators of the parameters in the longitudinal process model. This allows us to adapt the well-known empirical distribution function to estimate the duration distribution in the presence of missing time origin. Estimators with smooth realizations can then be obtained by conventional smoothing techniques. We establish the consistency and weak convergence of the proposed distribution estimator and present its variance estimation. We use a collection of wildland fire records from Alberta, Canada to motivate and illustrate the proposed approach. The finite-sample performance of the proposed estimator is examined by simulation. Viewing the available data as interval-censored times, we show that the proposed estimator can be more efficient than the well-established Turnbull estimator, an alternative that is often applied in such situations.
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Algoritmos , Canadá , Simulación por Computador , Humanos , Funciones de VerosimilitudRESUMEN
OBJECTIVE: This study aims to determine associations between anthropometric traits, regional fat depots and insulin resistance in children, adolescents and adults to define new cut-offs of body mass index (BMI) or waist circumference (WC). DESIGN: Cross-sectional data were assessed in 433 children, adolescents and adults (aged: 6-60 years, BMI: 23.6 [21.0-27.7] kg m-2). Total adipose tissue (TAT), regional subcutaneous adipose tissue (SATtotal, SATtrunk) and visceral adipose tissue (VAT) were determined by whole-body magnetic resonance imaging, fat mass by air-displacement plethysmography. Insulin resistance was evaluated by homeostasis model assessment of insulin resistance (HOMA-IR). Bivariate as well as partial correlations and regression analyses were used. Cut-off values of BMI and WC related to regional fat depots and HOMA-IR were analysed by receiver operating characteristics curve. RESULTS: In adults, TAT, SATtotal and SATtrunk increased linearly with increasing BMI and WC, whereas they followed a cubic function in children and adolescents with a steep increase at BMI and WC ≥1 standard deviation score and VAT at WC ≥2 standard deviation score. Sex differences were apparent in adults with women having higher masses of TAT and SAT and men having higher VAT. Using established BMI or WC cut-offs, correspondent masses of TAT, SATtotal, SATtrunk and VAT increased from childhood to adulthood. In all age groups, there were positive associations between BMI, WC, SATtrunk, VAT and HOMA-IR. When compared with normative cut-offs of BMI or WC, HOMA-IR-derived cut-offs of regional fat depots were lower in all age groups. CONCLUSIONS: Associations between BMI, WC and regional fat depots varied between children, adolescents, young and older adults. When compared with BMI-derived and WC-derived values, an insulin resistance-derived cut-off corresponded to lower masses of regional fat depots. Thus, established BMI and WC cut-offs are not appropriate to assess metabolic disturbances associated with obesity; therefore, new cut-offs of BMI and WC are needed for clinical practice.
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O cruzamento com a raça Jersey vem sendo utilizado principalmente como alternativa para o aumento da concentração de sólidos do leite em rebanhos puros Holandês, sendo a capacidade de produção desses animais conhecida em diversos estudos. Entretanto, ainda existem limitadas informações sobre diversos fatores relevantes para a tomada de decisão e para o manejo de rebanhos cruzados, tais como resistência a doenças e facilidade de parto, sendo esta a motivação do presente trabalho, o qual objetivou avaliar a sanidade, a imunidade e a facilidade de parto de vacas mestiças Holandês x Jersey em relação a vacas puras Holandês. Foram analisados dados de dificuldade de parto, duração da gestação, retenção de placenta, indicadores sanguíneos para doenças metabólicas pós-parto (cetose e paresia puerperal hipocalcêmica) e de imunidade obtidos em vacas mestiças Holandês x Jersey e puras Holandês durante o período de um ano. O grupamento genético não afetou a facilidade de parto (P=0,4376), a retenção de placenta (P=0,7074) e a duração da gestação (P=0,2812). Vacas mestiças apresentaram maiores concentrações de gamaglobulinas (1,776 contra 1,456g/dL) e de proteína total (7,019 contra 6,525g/dL). Quanto à concentração de ß-hidroxibutirato (BHBA), ocorreu diferença somente no dia do parto, com valores mais altos para as vacas mestiças (0,580 contra 0,427mmol/L). Observou-se diferença entre grupamentos genéticos para concentração de cálcio iônico (P=0,082), com vacas mestiças apresentando concentração mais baixa (3,92 contra 4,3 mg/dL). Conclui-se que vacas mestiças apresentam melhor performance em indicadores de imunidade e pior nos indicadores de cetose e paresia puerperal hipocalcêmica no pós-parto em relação às puras Holandês. O cruzamento não aumenta o risco de distocia em vacas inseminadas com touros Holandês.(AU)
The crossbreed with the Jersey breed has been used mainly as an alternative to increasing the concentration of milk solids in Holstein herds, the production capacity of these animals having become the focus of several studies. However, there is still limited information on many relevant factors for decision-making and management of crossbreed herds, such as disease resistance and ease of calving, and this is the motivation for this work, which aimed to evaluate the health, immunity and calving difficulty in Holstein x Jersey crossbred cows compared to pure Holstein cows. Data from calving difficulty, retained placenta, gestation length, blood indicators for postpartum metabolic diseases (ketosis and hypocalcemic puerperal paresis) and immunity in a herd composed by crossbreeds and Holstein cows during one year was analyzed. The genetic groups did not affect ease of calving (P = 0.4376), retained placenta (P = 0.7074) and gestation length (P=0.2812). Crossbred cows had higher concentrations of gammaglobulins (1.776 versus 1.456g/dL) and total protein (7.019 versus 6.525g/dL). For the concentration of BHBA, differences occurred only at calving, with higher values for crossbred cows (0.580 versus 0.427mmol/L). Difference was observed between genetic groups for concentration of ionized calcium (P = 0.082), with crossbred cows presenting lower concentrations (3.92 versus 4.3mg/dL). In conclusion, crossbred cows have superior performance compared to Holstein cows for immunity indicators and lower for hypocalcemic puerperal paresis and ketosis indicators on the day of calving. Crossbred cows do not have an increased risk of dystocia in relation to pure Holstein cows when mated with Holstein bulls.(AU)
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Animales , Femenino , Bovinos , Inmunidad/genética , Inmunoglobulinas , Cetosis/veterinaria , Parálisis de la Parturienta/genética , Retención de la Placenta/veterinaria , Periodo Posparto/genética , Cruzamientos GenéticosRESUMEN
BACKGROUND/OBJECTIVES: Bioelectrical impedance analysis (BIA) provides noninvasive measures of skeletal muscle mass (SMM) and visceral adipose tissue (VAT). This study (i) analyzes the impact of conventional wrist-ankle vs segmental technology and standing vs supine position on BIA equations and (ii) compares BIA validation against magnetic resonance imaging (MRI) and dual X-ray absorptiometry (DXA). SUBJECTS/METHODS: One hundred and thirty-six healthy Caucasian adults (70 men, 66 women; age 40±12 years) were measured by a phase-sensitive multifrequency BIA (seca medical body composition analyzers 515 and 525). Multiple stepwise regression analysis was used to generate prediction equations. Accuracy was tested vs MRI or DXA in an independent multiethnic population. RESULTS: Variance explained by segmental BIA equations ranged between 97% for total SMMMRI, 91-94% for limb SMMMRI and 80-81% for VAT with no differences between supine and standing position. When compared with segmental measurements using conventional wrist-ankle technology. the relationship between measured and predicted SMM was slightly deteriorated (r=0.98 vs r=0.99, P<0.05). Although BIA results correctly identified ethnic differences in muscularity and visceral adiposity, the comparison of bias revealed some ethnical effects on the accuracy of BIA equations. The differences between LSTDXA and SMMMRI at the arms and legs were sizeable and increased with increasing body mass index. CONCLUSIONS: A high accuracy of phase-sensitive BIA was observed with no difference in goodness of fit between different positions but an improved prediction with segmental compared with conventional wrist-ankle measurement. A correction factor for certain ethnicities may be required. When compared with DXA MRI-based BIA equations are more accurate for predicting muscle mass.
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Composición Corporal , Impedancia Eléctrica , Grasa Intraabdominal/fisiología , Músculo Esquelético/fisiología , Absorciometría de Fotón , Adolescente , Adulto , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
We present a miniaturized molecular beam epitaxy (miniMBE) system with an outer diameter of 206 mm, optimized for flexible and high-throughput operation. The three-chamber system, used here for oxide growth, consists of a sample loading chamber, a storage chamber, and a growth chamber. The growth chamber is equipped with eight identical effusion cell ports with linear shutters, one larger port for either a multi-pocket electron beam evaporator or an oxygen plasma source, an integrated cryoshroud, retractable beam-flux monitor or quartz-crystal microbalance, reflection high energy electron diffraction, substrate manipulator, main shutter, and quadrupole mass spectrometer. The system can be combined with ultrahigh vacuum (UHV) end stations on synchrotron and neutron beamlines, or equivalently with other complex surface analysis systems, including low-temperature scanning probe microscopy systems. Substrate handling is compatible with most UHV surface characterization systems, as the miniMBE can accommodate standard surface science sample holders. We introduce the design of the system, and its specific capabilities and operational parameters, and we demonstrate the epitaxial thin film growth of magnetoelectric Cr2O3 on c-plane sapphire and ferrimagnetic Fe3O4 on MgO (001).
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BACKGROUND/OBJECTIVES: Because both, glycemic index (GI) and carbohydrate content of the diet increase insulin levels and could thus impair fat oxidation, we hypothesized that refeeding a low GI, moderate-carbohydrate diet facilitates weight maintenance. SUBJECTS/METHODS: Healthy men (n=32, age 26.0±3.9 years; BMI 23.4±2.0 kg/m(2)) followed 1 week of controlled overfeeding, 3 weeks of caloric restriction and 2 weeks of hypercaloric refeeding (+50, -50 and +50% energy requirement) with low vs high GI (41 vs 74) and moderate vs high CHO intake (50% vs 65% energy). We measured adaptation of fasting macronutrient oxidation and the capacity to supress fat oxidation during an oral glucose tolerance test. Changes in fat mass were measured by quantitative magnetic resonance. RESULTS: During overfeeding, participants gained 1.9±1.2 kg body weight, followed by a weight loss of -6.3±0.6 kg and weight regain of 2.8±1.0 kg. Subjects with 65% CHO gained more body weight compared with 50% CHO diet (P<0.05) particularly with HGI meals (P<0.01). Refeeding a high-GI diet led to an impaired basal fat oxidation when compared with a low-GI diet (P<0.02), especially at 65% CHO intake. Postprandial metabolic flexibility was unaffected by refeeding at 50% CHO but clearly impaired by 65% CHO diet (P<0.05). Impairment in fasting fat oxidation was associated with regain in fat mass (r=0.43, P<0.05) and body weight (r=0.35; P=0.051). CONCLUSIONS: Both higher GI and higher carbohydrate content affect substrate oxidation and thus the regain in body weight in healthy men. These results argue in favor of a lower glycemic load diet for weight maintenance after weight loss.
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Tejido Adiposo/metabolismo , Glucemia/metabolismo , Peso Corporal , Dieta , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/metabolismo , Índice Glucémico , Adulto , Índice de Masa Corporal , Peso Corporal/efectos de los fármacos , Restricción Calórica , Carbohidratos de la Dieta/metabolismo , Carbohidratos de la Dieta/farmacología , Ingestión de Energía , Prueba de Tolerancia a la Glucosa , Humanos , Masculino , Oxidación-Reducción , Periodo Posprandial , Valores de Referencia , Aumento de Peso , Pérdida de Peso , Adulto JovenRESUMEN
Barefoot running and running using minimalist footwear have become increasingly popular in recent years. Footwear choice may affect running mechanics and the metabolic cost of running. To investigate these factors, 8 well-trained, female distance runners (mean age=20.1±1.4 years) were recruited to participate in the study. Following orientation to testing procedures, subjects completed 3 running economy tests on separate days. Treatment order (barefoot, minimalist footwear and running shoe) was counter-balanced. Each testing session consisted of a 5-min warm-up at 2.24 m · s(-1), followed by the 7-min RE test at 3.13 m · s(-1). Biomechanical data were collected at the 3-min mark for 10 s, and expired gases were collected from minutes 5-7. One-way repeated measures ANOVA revealed a statistically significant difference for running economy (p=0.04), expressed as relative oxygen uptake per km in the barefoot condition (running shoe: 204.51±2.84; minimalist footwear: 198.21±3.04; barefoot: 193.26±3.62 ml · kg(-1)· km(-1)) vs. running shoe. The other physiological and biomechanical variables were not statistically significant (p>0.05). However, moderate to large effect sizes suggested there were biomechanical changes that ensured between conditions. It should be further evaluated whether these mechanical adjustments and the running economy trend would translate into improved distance race performance while running barefoot or with minimalist footwear.
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Pie/fisiología , Marcha/fisiología , Carrera/fisiología , Zapatos , Adulto , Fenómenos Biomecánicos , Metabolismo Energético , Femenino , Humanos , Consumo de Oxígeno , Ventilación Pulmonar , Factores Sexuales , Adulto JovenRESUMEN
The phonon spectrum of Ge2Sb2Te5 is a signature of its crystallographic structure and underlies the phase transition process used in memory applications. Epitaxial materials allow coherent optical phonons to be studied in femtosecond anisotropic reflectance measurements. A dominant phonon mode with frequency of 3.4â THz has been observed in epitaxial Ge2Sb2Te5 grown on GaSb(001). The dependence of signal strength upon pump and probe polarization is described by a theory of transient stimulated Raman scattering that accounts for the symmetry of the crystallographic structure through use of the Raman tensor. The 3.4â THz mode has the character of the 3 dimensional T2 mode expected for the O(h) point group, confirming that the underlying crystallographic structure is cubic. New modes are observed in both Ge2Sb2Te5 and GaSb after application of large pump fluences, and are interpreted as 1 and 2 dimensional modes associated with segregation of Sb.
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BACKGROUND: The B-cell signature of tolerance in kidney transplant patients receiving no immunosuppression includes a significant increase in total CD19(+) B cells. METHODS: We evaluated kidney transplant recipients with primary functioning allografts for 30-44 years receiving minimal immunosuppression to determine whether they have the same CD19(+) B-cell changes or unusual serologic findings. We included 44 kidney allograft recipients with a graft functioning for 30-44 years, who were treated primarily with minimal prednisone and azathioprine. Twenty-four other recipients whose allografts functioned >30 years were unable to be studied (unable to travel, lost to follow-up, deceased). RESULTS: The number and percentage of CD19(+) B cells were depressed in 70.5% (31/44) and 81.8% (36/44), respectively, of these 44 ultra-long renal transplant recipients. The other major finding was identification by immunofixation of a monoclonal protein (MP) in 45.5% (20/44) of these same recipients. Among the 26 patients with good or excellent renal function (estimated glomerular filtration rate [eGFR] ≥ 45 mL/min/1.73 m(2); group 1), 12 had a single MP for >1 year, 13 no MP, and 1 a double MP. Conversely, in the 18 patients with fair/failed function (eGFR <40 mL/min/1.73 m(2) in 8, or end-stage renal disease after 30 years in 10; group 2), 3 had a transient single MP or free light chains only, 11 no MP, and 4 a double MP (P = .0425). CONCLUSIONS: These data reveal that about three quarters of ultra-long renal transplant recipients had low CD19(+) B cells, compared with the elevated B-cell signature reported in tolerant kidney recipients, and nearly half (45.5%) had a serum MP that was not associated with low B cells or mortality. Those with a stable single MP had better graft function.
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Anticuerpos Monoclonales/sangre , Antígenos CD19/inmunología , Linfocitos B/inmunología , Trasplante de Riñón , Adolescente , Adulto , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Tasa de SupervivenciaRESUMEN
BACKGROUND/OBJECTIVES: We intended to (i) to compare the composition of weight loss and weight gain using densitometry, deuterium dilution (D2O), dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI) and the four-compartment (4C) model and (ii) to compare regional changes in fat mass (FM), fat-free mass (FFM) and skeletal muscle as assessed by DXA and MRI. SUBJECTS/METHODS: Eighty-three study participants aged between 21 and 58 years with a body mass index range of 20.2-46.8 kg/m(2) had been assessed at two different occasions with a mean follow-up between 23.5 and 43.5 months. Body-weight changes within < 3% were considered as weight stable, a gain or a loss of >3% of initial weight was considered as a significant weight change. RESULTS: There was a considerable bias between the body-composition data obtained by the individual methods. When compared with the 4C model, mean bias of D2O and densitometry was explained by the erroneous assumption of a constant hydration of FFM, thus, changes in FM were underestimated by D2O but overestimated by densitometry. Because hydration does not normalize after weight loss, all two-component models have a systematic error in weight-reduced subjects. The bias between 4C model and DXA was mainly explained by FM% at baseline, whereas FFM hydration contributed to additional 5%. As to the regional changes in body composition, DXA data had a considerable bias and, thus, cannot replace MRI. CONCLUSIONS: To assess changes in body composition associated with weight changes, only the 4C model and MRI can be used with confidence.
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Tejido Adiposo , Composición Corporal , Compartimentos de Líquidos Corporales , Agua Corporal , Pesos y Medidas Corporales/métodos , Aumento de Peso , Pérdida de Peso , Absorciometría de Fotón/métodos , Adulto , Sesgo , Índice de Masa Corporal , Densitometría/métodos , Óxido de Deuterio , Impedancia Eléctrica , Femenino , Humanos , Técnicas de Dilución del Indicador , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Músculo Esquelético , ObesidadRESUMEN
BACKGROUND: Although weight cycling is frequent in obese patients, the adverse consequences on body composition and an increased propensity to weight gain remain controversial. OBJECTIVE: We investigated the effect of intentional weight loss and spontaneous regain on fat distribution, the composition of lean mass and resting energy expenditure (REE). DESIGN: Weight regainers (≥ 30% of loss, n=27) and weight-stable subjects (within <± 20% of weight change, n=20) were selected from 103 overweight and obese subjects (body mass index 28-43 kg m(-2), 24-45 years) who passed a 13-week low-calorie diet intervention. REE and body composition (by densitometry and whole-body magnetic resonance imaging) were examined at baseline, after weight loss and at 6 months of follow-up. RESULTS: Mean weight loss was -12.3 ± 3.3 kg in weight-stable subjects and -9.0 ± 4.3 kg in weight regainers (P<0.01). Weight regain was incomplete, accounting for 83 and 42% of weight loss in women and men. Regain in total fat and different adipose tissue depots was in proportion to weight regain except for a higher regain in adipose tissue of the extremities in women and a lower regain in extremity and visceral adipose tissue in men. In both genders, regain in skeletal muscle of the trunk lagged behind skeletal muscle regain at the extremities. In contrast to weight-stable subjects, weight regainers showed a reduced REE adjusted for changes in organ and tissue masses after weight loss (P<0.001). CONCLUSION: Weight regain did not adversely affect body fat distribution. Weight loss-associated adaptations in REE may impair weight loss and contribute to weight regain.
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Tejido Adiposo/patología , Metabolismo Basal , Obesidad/patología , Aumento de Peso , Pérdida de Peso , Adulto , Distribución de la Grasa Corporal , Índice de Masa Corporal , Restricción Calórica , Densitometría , Metabolismo Energético , Femenino , Alemania/epidemiología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Obesidad/dietoterapia , Obesidad/epidemiología , Recurrencia , Distribución por Sexo , Termogénesis/fisiologíaRESUMEN
The growth of Sb nanowires on GaSb(111)A substrates is studied by in situ azimuthal scan reflection high-energy electron diffraction (ARHEED). Bulk and layer contributions can be distinguished in the ARHEED transmission pattern through the Sb nanowires. The three-dimensional structure of the growing Sb nanowires is identified by post-growth atomic force microscopy (AFM) and x-ray diffraction (XRD). The lattice match of the Sb crystal along the [Formula: see text] and the GaSb crystal along [Formula: see text] directions lead to a preferential orientation of the Sb nanowires. The Sb adsorption and desorption kinetics is studied by thermal desorption spectroscopy.
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Antimonio/química , Cristalización/métodos , Galio/química , Nanoestructuras/química , Nanoestructuras/ultraestructura , Anisotropía , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Propiedades de SuperficieRESUMEN
AIM: The purpose of this investigation was to study the influence of prolonged low-intensity single scull rowing exercise on plasma adipocytokine and osteokine concentrations in trained male rowers. Nine single scull rowers (age: 20.1±1.6 yrs; height: 184.1±4.6 cm; body mass: 81.2±5.3 kg; %body fat: 11.1±3.9) participated in this study. METHODS: Venous blood samples were obtained before and after a ~2 h constant load on-water sculling training session (distance: 20.6±1.5 km; HR: 133±4 bpm; intensity: 80.3±1.7% of the HR turn-point). RESULTS: The training session created an energy deficit of 1 200-1 500 kcal. Plasma adiponectin increased (+12.2%; P<0.05) while leptin decreased (-23.1%; P<0.05) at 30 min postexercise. Plasma osteocalcin (+23.7%; P<0.05) and type I carboxyterminal telopeptide (ICTP) (+28.6%; P<0.05) were increased on completion of the training session. Plasma IL-6 concentration was increased (P<0.05) about four-fold while insulin concentration was decreased (P<0.05) more than three-fold upon completion of exercise. There were no differences in TNF-α, glucose, testosterone and cortisol concentrations over time. Plasma adiponectin (r=0.59) and osteocalcin (r=0.57) concentrations measured immediately after the training session were related (P<0.05) to the distance covered. CONCLUSION: Acute negative energy balance induced by a single endurance rowing training session elicited an inverse metabolic response in adiponectin and osteocalcin concentrations in male rowers. Our results suggest that peripheral markers of negative energy balance, such as adiponectin and osteocalcin, may serve as signals for metabolic reaction to the energy cost of acute exercise in athletes.
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Adiponectina/sangre , Leptina/sangre , Osteocalcina/sangre , Deportes/fisiología , Adolescente , Biomarcadores/sangre , Humanos , Insulina/sangre , Masculino , Adulto JovenRESUMEN
To evaluate the effects of a 12-month exercise intervention using either high-impact step aerobic exercise or moderate-intensity strength training on areal bone mineral density (aBMD) we studied 51 untrained women, aged 20-35 years, for this study. Whole body and heel and wrist aBMD were measured by dual-energy X-ray absorptiometry (DXA, Hologic or PIXI Lunar). Subjects were randomly assigned to: impact-loaded step aerobic exercise (SA, n=15), moderate-intensity lower body strength training (ST, n=16) or non-exercise control (CON, n=20). Data analysis only included those who completed 95% of each training routine and attended at least 80% of all sessions. Group differences in aBMD, leg press strength and urinary cross-link deoxypridinoline (µDPD) were analysed using analysis of variance. After a 12-month intervention, the SA elicited an increase in aBMD of the heel (4.4%, p<0.05) and leg press strength (15%, p<0.05), relative to baseline. Meanwhile, the ST showed an increase in leg press strength (48%, p<0.05) with no significant increase in aBMD at any measured site. Similar and unchanged µDPD was observed in all 3 groups at baseline, 6 and 12 months. In conclusion, a 12-month high-impact step aerobic exercise resulted in a significant increase in the heel aBMD in untrained young women, who complied with the exercise regimen. A moderate intensity strength training intervention of similar duration had no effect on aBMD although leg strength increased significantly.
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Densidad Ósea/fisiología , Ejercicio Físico/fisiología , Entrenamiento de Fuerza , Absorciometría de Fotón , Adulto , Aminoácidos/orina , Biomarcadores/orina , Estatura , Peso Corporal , Calcio de la Dieta/administración & dosificación , Creatinina/orina , Registros de Dieta , Femenino , Humanos , Fuerza Muscular/fisiología , Aptitud Física , Premenopausia , Soporte de Peso/fisiología , Adulto JovenRESUMEN
BACKGROUND: Although our understanding of the risk factors involved in the occurrence of posttransplant diabetes mellitus (PTDM) as well as its outcomes has improved, it still remains incomplete. Our study attempts to analyze the risk factors as well as the outcomes associated with PTDM in the renal transplant patients at the Cleveland Clinic. METHODS: Our study is a retrospective, case-control study. We screened 209 charts of 217 patients who received single-organ kidney transplant at the Cleveland Clinic between January 1996 and December 1998. PTDM was defined by the American Diabetes Association criteria of either a fasting blood glucose >or=126 mg/dL or random blood sugars >or=200 mg/dL confirmed on a second occasion. Kidney transplant recipients who developed PTDM (cases) were compared with kidney transplant recipients who did not develop diabetes but were matched for the time of transplant (controls). RESULTS: Forty-nine patients (23%) developed PTDM. The data of 47 cases and 47 controls were analyzed. Age >or=40 years, body mass index >or=30, pretransplant triglyceride levels >150 mg/dL, and presence of graft rejection were significant risk factors for developing PTDM. Smoking was associated with increased risk of PTDM but failed to achieve statistical significance. Compared with controls, PTDM patients had higher risk of cardiovascular disease, infections, and graft rejection. CONCLUSION: Our results show that PTDM is a significant problem after kidney transplantation, and those who have high risk should be closely monitored after transplant and aggressively treated if they develop diabetes to minimize the risk of complications.
Asunto(s)
Diabetes Mellitus/epidemiología , Trasplante de Riñón/efectos adversos , Complicaciones Posoperatorias/epidemiología , Adulto , Glucemia/metabolismo , Índice de Masa Corporal , Estudios de Casos y Controles , Puente de Arteria Coronaria , Creatinina/sangre , Infecciones por Citomegalovirus/epidemiología , Diabetes Mellitus/sangre , Diabetes Mellitus/etiología , Rechazo de Injerto/epidemiología , Hepatitis C/epidemiología , Humanos , Trasplante de Riñón/estadística & datos numéricos , Persona de Mediana Edad , Proteinuria/epidemiología , Reoperación/estadística & datos numéricos , Estudios Retrospectivos , Factores de Riesgo , Resultado del Tratamiento , Triglicéridos/sangreRESUMEN
HfO(2) thin films of different thicknesses and deposited by two methods (ALD and MOCVD) were studied. The microstructure of films was characterized by reflection spectroscopy, x-ray diffraction (XRD), and soft x-ray reflectometry. It was established that the HfO(2) film microstructure is closely dependent on film thickness. The 5 nm thick film synthesized by ALD shows an amorphous phase while the film prepared by MOCVD was inhomogeneous in depth and showed signs of crystalline structure. First results on the reconstruction of the depth distribution of chemical elements based on the analysis of reflectivity curves are discussed.